Date: 11 March 2008
References: ESB-2008.0287 AU-2008.0005
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A U S C E R T A L E R T
AL-2008.0025 -- AUSCERT ALERT
[Win][OSX]
MS08-014 Vulnerabilities in Microsoft Excel Could Allow
Remote Code Execution
12 March 2008
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AusCERT Alert Summary
---------------------
Product: Microsoft Office 2000 Service Pack 3
Microsoft Office XP Service Pack 3
Microsoft Office 2003 Service Pack 2
2007 Microsoft Office System
Microsoft Office Excel Viewer 2003
Microsoft Office Compatibility Pack for Word, Excel,
and PowerPoint 2007 File Formats
Microsoft Office 2004 for Mac
Microsoft Office 2008 for Mac
Publisher: Microsoft
Operating System: Windows
Mac OS X
Impact: Execute Arbitrary Code/Commands
Access: Remote/Unauthenticated
CVE Names: CVE-2008-0111 CVE-2008-0112 CVE-2008-0114
CVE-2008-0115 CVE-2008-0116 CVE-2008-0117
CVE-2008-0081
Original Bulletin:
http://www.microsoft.com/technet/security/bulletin/MS08-014.mspx
Comment: As a best practice, Administrators should consider blocking or
quarantining binary and executable file formats to limit the risk of
exposure.
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MS08-014 Vulnerabilities in Microsoft Excel Could Allow Remote Code Execution
(949029)
Published: March 11, 2008
Version: 1.0
This security update resolves several privately reported
and publicly reported vulnerabilities in Microsoft Office
Excel that could allow remote code execution if a user
opens a specially crafted Excel file. An attacker who
successfully exploited these vulnerabilities could take
complete control of an affected system. An attacker could
then install programs; view, change, or delete data; or
create new accounts with full user rights. Users whose
accounts are configured to have fewer user rights on the
system could be less impacted than users who operate with
administrative user rights.
This security update is rated Critical for Microsoft Office
Excel 2000 Service Pack 3 and rated Important for Excel
2002 Service Pack 3, Excel 2003 Service Pack 2, Excel
Viewer 2003, Excel 2007, Microsoft Office Compatibility
Pack for Word, Excel, and PowerPoint 2007 File Formats,
Office 2004 for Mac, and Office 2008 for Mac.
Affected Software
o Microsoft Office 2000 Service Pack 3
o Microsoft Office XP Service Pack 3
o Microsoft Office 2003 Service Pack 2
o 2007 Microsoft Office System
o Microsoft Office Excel Viewer 2003
o Microsoft Office Compatibility Pack for Word, Excel, and
PowerPoint 2007 File Formats
o Microsoft Office 2004 for Mac
o Microsoft Office 2008 for Mac
Vulnerability Information
Excel Data Validation Record Vulnerability - CVE-2008-0111
A remote code execution vulnerability exists in the way Excel
processes data validation records when loading Excel files into
memory. An attacker could exploit the vulnerability by sending a
malformed file which could be hosted on a specially crafted or
compromised Web site, or included as an e-mail attachment.
Workarounds for Excel Data Validation Record Vulnerability - CVE-2008-0111
Microsoft has tested the following workarounds and states in the discussion
whether a workaround reduces functionality:
o Use Microsoft Office File Block policy to block the opening of Office
2003 and earlier documents from unknown or untrusted sources and
locations
The following registry scripts can be used to set the File Block policy.
For Office 2003
Windows Registry Editor Version 5.00
[HKEY_CURRENT_USER\Software\Microsoft\Office\11.0\Excel\Security\FileOpenBlock]
"BinaryFiles"=dword:00000001
Note In order to use 'FileOpenBlock' with Office 2003, all
of the latest Office 2003 security updates must be applied.
Impact of Workaround: Users who have configured the File
Block policy and have not configured a special exempt
directory as discussed in Microsoft Knowledge Base Article
922848 will be unable to open Office 2003 files or earlier
versions in Office 2003 or 2007 Microsoft Office System.
o Do not open or save Microsoft Office files that you receive from
untrusted sources or that you receive unexpectedly from trusted
sources. This vulnerability could be exploited when a user opens a
specially crafted file.
Excel File Import Vulnerability - CVE-2008-0112
A remote code execution vulnerability exists in the way Excel
handles data when importing files into Excel. An attacker could
exploit the vulnerability by sending a malformed .slk file which
could be hosted on a specially crafted or compromised Web site,
or included as an e-mail attachment, and which could then be
imported into Excel.
Workarounds for Excel File Import Vulnerability - CVE-2008-0112
o Do not open or save Microsoft Office files that you receive from
untrusted sources or that you receive unexpectedly from trusted
sources. This vulnerability could be exploited when a user opens
a specially crafted file.
Excel Style Record Vulnerability - CVE-2008-0114
o A remote code execution vulnerability exists in the way
Excel handles Style record data when opening Excel files. An
attacker could exploit the vulnerability by sending a malformed
file which could be hosted on a specially crafted or compromised
Web site, or included as an e-mail attachment.
Workarounds for Style Record Vulnerability - CVE-2008-0114
o Use the Microsoft Office Isolated Conversion Environment (MOICE)
when opening files from unknown or un-trusted sources
o Use Microsoft Office File Block policy to block the opening of Office
2003 and earlier documents from unknown or untrusted sources and
locations
Excel Formula Parsing Vulnerability - CVE-2008-0115
o A remote code execution vulnerability exists in the way Excel
handles malformed formulas. An attacker could exploit the
vulnerability by sending a malformed file which could be hosted
on a specially crafted or compromised Web site, or included as
an e-mail attachment.
Workarounds for Excel Formula Parsing Vulnerability - CVE-2008-0115
o Use Microsoft Office File Block policy to block the opening of Office
2003 and earlier documents from unknown or untrusted sources and
locations
Excel Rich Text Validation Vulnerability - CVE-2008-0116
o A remote code execution vulnerability exists in the way
Excel handles rich text values when loading application
data into memory. An attacker could exploit the
vulnerability by sending a malformed file which could
be hosted on a specially crafted or compromised Web site,
or included as an e-mail attachment.
Workarounds for Excel Rich Text Validation Vulnerability - CVE-2008-0116
o Use Microsoft Office File Block policy to block the opening of Office
2003 and earlier documents from unknown or untrusted sources and
locations
Excel Conditional Formatting Vulnerability - CVE-2008-0117
o A remote code execution vulnerability exists in the way
Excel handles conditional formatting values. An attacker
could exploit the vulnerability by sending a malformed
file which could be hosted on a specially crafted or
compromised Web site, or included as an e-mail
attachment.
Workarounds for Excel Conditional Formatting Vulnerability - CVE-2008-0117
o Do not open or save Microsoft Office files that you receive from
untrusted sources or that you receive unexpectedly from trusted
sources. This vulnerability could be exploited when a user opens a
specially crafted file.
Macro Validation Vulnerability - CVE-2008-0081
o A remote code execution vulnerability exists in the way
Excel handles macros when opening specially crafted Excel files.
An attacker could exploit the vulnerability by sending a
malformed file which could be hosted on a specially crafted or
compromised Web site, or included as
an e-mail attachment.
Workarounds for Macro Validation Vulnerability - CVE-2008-0081
o Use the Microsoft Office Isolated Conversion Environment (MOICE)
when opening files from unknown or un-trusted sources
o Use Microsoft Office File Block policy to block the opening of Office
2003 and earlier documents from unknown or untrusted sources and
locations
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The University of Queensland
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